Signaling system.



PATENTED JUNE 30, 1 903..

H. G. BROWN. SIGNALING SYSTEM. APPLICATION FILED 0013.10 1902.

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No. 732,272. 7 PATENTED JUNE 30, 1903.

' H.-G. BROWN.

SIGNALING SYSTEM. 7 APPLICATION nun 0'OT.10, 1902.

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UNITED STATES Patented Zl'une 30, 1203 PATENT OFFICE.

HAROLD G. BROWN, OF MELROSE, MASSAOHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO PAUL WINSOR, OF WESTON, MASSACHUSETTS.

SIGNALING SYSTEM.

SIPECIFICATION forming part of Letters Patent No. 732,272, dated June 30, 1903.

Application filed October 1O 1902. Serial No. 126,698. (No model.)

To all whom, it may concern: 5

Be it known that I, HAROLD G. BROWN, a citizen of the United States, residing in Mel- 'rose, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Signaling Systems, of which the following description, in connection with the accompanying drawings, is a specification, like charaters on the drawings representing like parts. 7

This invention relates to a system of signaling for use on railways employing the block signal system.

The present invention is especially adapted for use on electric railways which employ-one of the rails as the return for the current employed to operate the cars and which electric railways are provided with a block system the signals of which are operated by a signalingcurrent of the same character as the current which operates the cars.

Electric-railway systems as now commonly constructed and known to me employ a direct current to operate the cars and a like current to operate the signals, the potential of the signaling-current being materially less than the potential of the current employed to operate the cars, which latter current will be hereinafter designated the power or track current.

The signaling system of electric railways as now commonly constructed and employing a direct current for both the power and the signal service is defective in that the return track-current is liable to operate the signal system and cause the latter to indicate a clear track when a train is in a block.

The present invention has for its object to overcome this defect in systems of the class describednamely, those employing a direct current for both power and signal service and to overcome it at a minimum expense to the railway system and in such manner as will enable the direct current to be employed for both the power and signal service. For this purpose the signal magnet or relay now in common use is included in a local circuithaving, preferably, aplurality of circuit-controllers in series with one another and operatively con-' trolled by relays or translating devices in circuit with. the track'and having polarized armatures which govern the operation of thecircuit-controllers for the signal magnet or relay, the circuits of the said armatures being controlled by the track-relays, as will be described. .Theseand otherfeatures of'this invention will be pointed out in the claims at the end of this specification.

Figure 1 is a diagrammatic view of a sufficient portion of a block-signaling system embodying. this invention to enable it to be understood, the parts being in what may be termed their normal position with the block clear; Fig. 2, a view similarto Fig. 1, showing a train or car in the block; and Fig. 3, a modification to be referred to.

Referring to Fig. 1, a I) represent the rails of a track provided with a block-signal system, the rail 1) being provided with suitable insulation 0, which separates the track into blocks. In the present instance one complete block and parts of adjacent blocks are shown. These blocks are numbered 1 2 3, the block 2 being complete. The power-current is obtained from a direct-current generator d, hav- 7 5 ing its positive brush 6 connected to the third rail or trolley-wire f and its negative brush g connected to the rail a. The contact-shoe or trolley-wheel which carries the current from the supply-conductor f to the motor on the car h is represented by 2'. The signal-current is obtained from a direct-current generator j, which has its positive brush 70 connected to the rail a and its negative brush Z connected to the negative main m for the signal-current. Each block of the signal system in accordance with this invention has included in it two relays n 0, and, as represented in Figs. 1 and 2, one end of the coil of the relay n is connected by wire 19 to the rail a near one end of the 0 block 2, and the other end of the said coil is connected by wire (1 to the signal-rail Z) near the same end of the block 2. One end of the coil of the relay 0 is connected by wire 4" to the rail 01, near the opposite end of the block 2, 5 and the other end of the said coil is connected by wire 8 to the rail 1) near the same end of the block 2. The relays n o are provided with polarized armatures 5 7 which are pivoted at S 9 to cooperate with the pole-pieces 1O 12 of ICC the said relays and which have extended from them arms 13 14, constituting circuit-controllers for a local circuit containing a magnet or other translating device 15, governing the operation of the signal, which latter is represented as a semaphore 16. The polarized armatures 5 7 are provided with coils 17 18,which are included in circuits controlled by the armatures 1f) 20 of the relays n 0. The armature 19 governs the operation of a circuit-controller, represented as a contact-piece 21 on the end of a rod or arm 22, attached to the armature 19, the said contact-piece cooperating; with a contact-piece 23, connected by the wire 240 with the rail a. The armature 2O governs the operation of a similar circuit-controller, represented as the contact-piece 24 on a rod 25, attached to the armature 20, the contact 24 cooperating with a contact-piece 26, connected by the wire 27 with the rail a. The coil 17 of the polarized armature 5 has one of its ends connected by wire 28 to the contact piece or member 21 and its other end connected by wire 29 to the negative main m. The coil 18 of the polarized armature 7 has one of its ends 0011- nected by wire 30 with the contact-piece 24 and its other end connected by the wire 31 with the negative main. The circuit-c011- trollers 13 14, which are operated by the polarized armatures 5 7, govern the local circuit containing the signal-magnet or translating device 15, and, as herein represented, the circuit-controllers 13 14 are provided with contacts 32 which cooperate with contacts 34 35, the contact 34 in the present instance being connected by wire 36 with the negative main m, and the contact 32 connected by wire 37 with the contact 35, and the contact 33 connected by wire 38 with one end of the coil of the magnet 15, the other end of which is connected by wire with the rail a. The negative main m is further connected with the rail 1) of each block-section by a wire 40, which may and preferably will include a resistance 41 of any suitable or usual construction.

The operation of the signal system herein shown may be readily understood by reference to Figs. 1 and 2. In Fig. 1 the parts of the system are shown in the position they occupy when the block-section 2 is clear, which may be considered the normal condition. In this case the relays n are energized by the direct-signal current from the generator 7', and the polarized armatures 7 are attracted to the proper polesnamely, the poles ]2to maintain closed the local circuit containing the signal-magnet. The course of the signal-current through the relays may be traced as follows-na1nely, from the positive brush of the generator j to the rail (1., thence by the wires 19 r, in multiple, through the relays no, to the rail-section I) by the wires 1 s, and from the railsection I), through the wire 40, resistance 41, and negative main m, back to the generator j. The course of the current through the signal-magnet may be traced as followsnamely, from the positive brush of the generatorj to the rail a, thence by the wire 3!), through the magnet 15, wire 38, contacts 35, wire 37, contacts 32 34, wire 36, to the negativemain m and thence back to the negative brush of the generatorj. The course of the current through the coils of the polarized armatures may be traced as follows: from the positive brush of the generator j to the rail a, thence by the wires 240 27 to the contacts 23 26, thence by the contacts 21 24, wires 28 30, through the coils 17 18 and by wires 29 31 t0 the negative main m, and thence back to the negative brush of the generatorj. If a train enters the block moving in the direction indicated by the arrow 100 and, for instance, as indicated in Fig. 2, the relays n 0 are short circuit as to the signalcurrent, and thereby denergized, which permits the armatures 19 to drop by gravity, and thereby open the circuit of the coils 17 18 of the polarized armatures between the contacts 21 23 and 24 26 and the polarized armatures are moved from the position shown in Fig. l to that shown in Fig. 2 by weights 45 on the controller-arms 13 14 or it may be by springs or in other suitable manner, thereby opening the circuit of the local. The short circuit for the signal-current may be traced as follows: from the rail a through the trucks of the car in the block 2 to the rail 1) of the said block, thence by the said rail to the wire 40, thereby short-circuiting the point of connection of the wires 3 and q with the rail b, and consequently short-circuiting the relays 0 and 11. Let it be assumed that the current returning to the power-station returns through the rail a, and produces a drop of potential along it, so that there would be an appreciable difference of potential between the points of connection of the wires 1' and p with the rail a. Suppose While the train is in the block adirect current extraneous to the signal-current flows along the rail a in the direction indicated by the arrow 100. In this case the potential of the rail 7) to the rail a depends on the location of the car-truck h. If the truck is located at the right-hand end of the block, as shown in Fig. 2, the signalrail 1) will have at this end the same potential as the rail to at that point, while at the left-hand end of the block the rail 1; will have the same potential as the rail a at the truck 71, which is a different potential from that of the rail a opposite the left-hand end of the block-section. Consequently there will be a flow of current due to this diiference of potential from the rail a, through the truck h, along the rail 1) to the wire q, through the relay a to the wire pand rail a, which will energize the relay n and attract the armature l9,thereby closing the local circuit at the contacts 21 23. If the direction of this return-current is of the proper sign, it may attract the polarized armature 5 into the position indicated in Fig. 1, and thereby close the local between the points 32 34, or if the current is of the opposite sign or direction, which latter is the case in the present instance, owing to the location of the generator cl in the drawings, then it will reverse the polarity of the relay n and cause the polarized armature 5 to remain in its denergized position, thereby maintaining the circuit of the local open between the points 32 34. In either event thesignal at danger is unaifected by the return extraneous direct current, owing to the fact that the circuit of the local containing the signal-magnet is opened between the points 33 35 irrespective of the condition of the contacts 42 34, the extraneous current in this case having no effect upon the relay 0, the terminal wires 7" s of which are of the same potential, being shortcircuited by the truck h. Now, then, as the train passes away from the vicinity of the relay o and approaches the vicinity of the relay n the shunting eifect of the truck h on the relay 0 is gradually diminished with reference to the extraneous current, and the potential difference between the wires 0" and s is being gradually increased, thereby establishing a flow of the extraneous direct current through the previously-shunted relay 0, under these conditions, in the normal direction, which would move the polarized armature 7 intowhat may be termed its normal position, (shown in Fig. 1,) thereby closing the circuit of the local between the points 33 35; but the local is still held open between the contacts 32 34: by the reversal of the relay n until the latter is shunted. If the extraneous current enters the signal-rail when the train is near the center of the block, the extraneous current will flow through one of the relays in the normal direction and through the other relay in the reverse direction, so that the circuit of the local is open at least at one point. It will thus be seen that when the train is on the block an extraneous direct current on the signal-rail can have no influence on the signal-magnet, which is safeguarded by its circuit being open at one or more points, so that the signal cannot be energized to indicate a clear track while a train is on the block. It will be seen that when a train is on the block and an extraneous direct current flows through the wheels onto the signal-rail either one of the relays is shunted, thereby deenergizing the same and opening the local of the signal-magnet, or the current through one of the relays is reversed, which causes the polarized armature to be moved from its normal position (shown in Fig. 1) to the position shown in Fig. 2. It is manifest that an extraneous direct current from any other source than from the return of the power-generator, which may get onto the signal-rail, will act in the manner above described.

In Figs. 1 and 2 the relays n and o are shown as connected to the rails a and 1) near the opposite ends of the blocks by the wires 19, q, r, and s, in which case the relays may be located at opposite ends of the block; but, if desired, the wire (1 may be disconnected from the rail 1) near its end of the block and connected with the wire 8 of the relay 0, as represented in Fig. 3, which permits both relays to be located near together and, if desired, near the center of the block.

The signaling system herein shown and described is arranged to operate with the extraneous current flowing in one direction along the block.

I have herein shown a block as provided with two relays; but I do not desire to limit my invention in this respect, as additional relays may be used for the purpose of enablin g the system to operate when the returncurrent flows in opposite directions in diiferent portions of the block at the same time.

In the present instance the power-current is the extraneous current to be guarded against; but the system is equally adapted to guard the signal from any current foreign to the signal-current and which might get onto the signal-rail of the system.'

1. In a signalingsystem of the class described, in combination, a power-circuit including a rail of a track, a source of direct current in circuit with said power-circuit, a circuit including a block-section of the other rail of the track and a source of direct current, a local circuit, a translating device in said local circuit governing the operation of a signal, and means responsive to a direct signal-current for maintaining the said local circuit in one condition to indicate a clear block, and responsive to a direct current extraneous to the direct signal-current to place the local circuit in a changed condition to indicate an occupied condition of the block when a shunt exists on the track-circuit and irrespective of the polarity of the extraneous direct current, substantially as described.

2. In a signaling system of the class described, in combination, a power-circuit including a rail of a track, a source of direct current in circuit with said power-circuit, a circuit including a block-section of the other rail of the track and a source of direct current, a local circuit, a translating device in said local circuit for controlling the operation of a signal, and a plurality of translating devices in circuit with the block-section and responsive to a direct signal-current to maintain the local circuit in condition to indicate a clear block and responsive to a direct current extraneous to the direct signal-current to change the condition of the local circuit and thereby indicate that the condition of the block is different, substantially as described.

3. In a signaling system of the class described, in combination, a block-section of a track, a source of direct current in circuit with said block-section, a signal, atranslating device governing the operation of said signal, a local circuit in which said translating device is included, a plurality of relays in circuit with the block-section, polarized armatures for said relays, a plurality of circuitcontrollers operated by said polarized armatures and controlling the local circuit of said signal-magnet, substantially as described.

4. In a signaling system of the class described, in combination, a signal,a translating device controlling the operation of said signal, a circuit in which said translating device is included, a plurality of circuit-controllers in series in said circuit, a plurality of polarized armatures for operating said circuit-controllers, coils on said armatures, circuit-controllers governing the circuits of the polarized armature-coils, a plurality of relays, armatures for said relays governing the operation of the circuit-controllers for said polarized armature-coils, a circuit including the rails of a track and said relays, and a source of direct current in circuit with said track-circuit, for the purpose specified.

5. In a signaling system of the class described, in combination, a track-circuit, a

source of direct current included in said track-circuit, a signal-magnet or translating device, a separate circuit in which said signal-magnet is included, and means responsive to a direct current for maintaining the circuit of the signal-magnet in one condition to indicate a clear block, and responsive to an extraneous direct current to place the circuit of the signal-magnet in another condition to indicate an occupied condition of the block, when a shunt exists on the track-circuit of the block and irrespective of the polarity of the extraneous direct current, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HAROLD G. BROWN.

Witnesses:

J AS. H. CHURCHILL, J. MURPHY. 

